1. Field of the Invention
The present invention relates to a softener composition which makes it possible to impart softness and antistatic properties to a variety of clothing and in particular to a softener composition capable of improving the water absorption properties of clothing without impairing softness and antistatic properties thereof.
2. Description of the Prior Art
There have been employed various kinds of softeners in order to impart softness and antistatic properties to clothing after washing. These softeners in general comprise a di(long alkyl chain) di(short alkyl chain) quaternary ammonium salt or an imidazolinium salt as a principal component. In particular, the former has widely been utilized because of its excellent softness improving ability. The compound is adsorbed onto the surface of fibers and imparts good softness thereto. However, at the same time it also imparts water repellency thereto because of its high lipophilic nature. This leads to a reduction in the rate of water absorption of the textile goods treated with a softener containing such a cationic surfactant and the decrease in the amount of absorbed water per unit time or the apparent water absorption.
Accordingly, in order to solve the above problems of the conventional softener, many attempts have been directed to the development of novel cationic surfactants having a high compatibility with water so that the apparent water absorption of textile goods is not reduced (Japanese Patent Un-examined Publication (KOKAI) Nos. 55-66546; 56-92251 and 59-30965). In addition, attempts have been made to use the di(long alkyl chain) di(short alkyl chain) quaternary ammonium salt in combination with another surfactant of high compatibility with water. For instance, it has been combined with a fatty ethanolamide polyglycol ether (Japanese Patent Un-examined Publication No. 56-20677) and with a glycerin ether (Japanese Patent Un-examined Publication No. 56-20678).
However, since novel cationic surfactants have to sufficiently be investigated on their ability to impart intended properties such as softness, antistatic properties and apparent water absorption to chemical fibers or further with respect to the influence on the human body, only a few of them have been practically employed. In this connection, there have been known Varisoft 3690 and Rewoquat W3690 (respectively manufactured and sold by Sherex Chemicals (U.S.A.) and Rewochemische Werke (West Germany)) which are methyl-1-oleylamidethyl-2-oleylimidazolinium methyl sulfate (iodine value=80 to 90). However, if this is used alone, it cannot impart sufficient antistatic properties to chemical textile goods as will be explained below. Therefore, it should be used in combination with other cationic or nonionic softener. On the other hand, the use of the combination of di(long alkyl chain) di(short alkyl chain) quaternary ammonium salt and another surfactant of high compatibility with water makes it possible to impart an excellent softness comparable to that of the quaternary ammonium salt to textile goods, while it is difficult to surely prevent the reduction in the apparent water absorption. Thus, there has not yet been developed a softener composition practically acceptable.
Under such circumstances, the inventors of this invention conducted various studies to develop a softener composition capable of imparting not only excellent softness and antistatic properties but also sufficient water absorption properties to textile goods, which is thus of much practical usefulness, and as a result, have proposed a softener composition in which a di(long alkyl/alkenyl chain) di(short chain) quaternary ammonium salt having unsaturated bonds and a polyoxyethylene adducted type nonionic surfactant are used in combination (Japanese Patent un-examined Publication No. 61-160482). However, as a result of subsequent investigation, it has been found that this composition is effective in improving softness of natural fiber products such as cotton and in maintaining the water absorption thereof, but is incomplete in the improvement of the softness and antistatic properties of chemical textile goods.